Italian ad agency Enfants Terribles specializes in viral advertising. And to practice what they preach, the company's business cards are printed on lab slides and feature a fake company name—Ebolaindustries—and pseudonyms for all its staff, like Mrs. Grey.

If you want to know Mrs. Grey's real identity, you'll have to place the business card under a real working microscope where her actual name has been printed smaller than can be seen with the naked eye. Maybe a little annoying if—like everyone else on Earth who isn't a scientist—you don't have a microscope at your desk. But a clever idea that's successfully spreading the company's work across the internet—in what some might call a 'viral' fashion.